How important is a rear sway bar?
The purpose of a stabilizer bar is to reduce body roll at the rear of the vehicle. As the vehicle is driven around a corner, the bar acts as a lever that presses the inside wheel towards the ground in order to reduce excess body movement and keep the tire in contact with the ground. via
Is front or rear sway bar better?
Typically, a rear wheel drive car will handle better with a front sway bar that is stiffer than the OEM piece. Some rear wheel drive cars, however, also understeer. If your vehicle understeers, front or rear wheel drive, a stiffer rear sway bar will make the car handle more neutrally. via